title: Serum soluble interleukin-6 receptor and biochemical markers of bone metabolism show significant variations during the menstrual cycle.
abstract: We examined sequential changes of bone-resorbing cytokines and bone metabolic markers and the effect of ovarian hormones on bone metabolism during the menstrual cycle in 10 healthy Japanese women, aged 22-43 yr, with normal ovarian function. Serum soluble interleukin-6 receptor (sIL-6R) showed a significant variation; a rise during the early and late follicular periods followed by a fall during the early luteal period (P = 0.0423, P = 0.0334) and an increase during the mid and late luteal periods. There were significant changes in the levels of markers of bone formation: a rise in serum bone-specific alkaline phosphatase (ALP) during the mid and late follicular (P = 0.0265) periods and a fall in serum carboxyl-terminal propeptide of type I procollagen (PICP) during the midluteal period (P = 0.0161). As for the levels of bone resorption markers, urinary type I collagen C-telopeptide breakdown products (CTx) and free deoxypyridinoline (D-Pyr) decreased significantly during the early and midfollicular periods, urinary free D-Pyr and serum pyridinoline cross-linked carboxyl-terminal telopeptide of type I collagen (ICTP) (P = 0.0440) increased significantly during the early luteal period, and urinary CTx, free D-Pyr, and serum ICTP decreased significantly during the late luteal period (P = 0.0170-0.0008). The serum PTH level was significantly higher during the follicular than the luteal period (P = 0.0132). Serum sIL-6R significantly correlated with urinary CTx (r = 0.190, P < 0.05) and serum ALP (r = 0.209, P < 0.05) and serum estradiol with intact osteocalcin (r = 0.309, P < 0.0005) and serum ALP (r = 0.181, P < 0.05). These observations strongly suggest that cyclic variations in the levels of bone formation and resorption markers and of a bone-resorbing cytokine may be modulated by cyclic changes in serum steroid hormones during the menstrual period. In addition, the specific days of biochemical events in the menstrual cycle are crucial for evaluating osteoclastic and osteoblastic activities in pre- and perimenopausal women or in women starting GnRH agonist therapy.
authors.affiliation: Department of Obstetrics and Gynecology, Yokohama City University School of Medicine, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Gorai
authors.forename: Y
authors.initials: Y
authors.lastname: Taguchi
authors.forename: O
authors.initials: O
authors.lastname: Chaki
authors.forename: R
authors.initials: R
authors.lastname: Kikuchi
authors.forename: M
authors.initials: M
authors.lastname: Nakayama
authors.forename: B C
authors.initials: BC
authors.lastname: Yang
authors.forename: S
authors.initials: S
authors.lastname: Yokota
authors.forename: H
authors.initials: H
authors.lastname: Minaguchi
mesh_terms: D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood; D000596:Amino Acids / Q000097:blood; D015415:Biomarkers; D016723:Bone Remodeling; D001842:Bone and Bones / Q000378:metabolism*; D003094:Collagen / Q000652:urine; D024042:Collagen Type I; D004958:Estradiol / Q000097:blood; D005260:Female; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D008597:Menstrual Cycle / Q000378:metabolism*; D015675:Osteocalcin / Q000097:blood; D010281:Parathyroid Hormone / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D010455:Peptides / Q000652:urine; D011347:Procollagen / Q000097:blood; D011374:Progesterone / Q000097:blood; D019947:Receptors, Interleukin-6 / Q000097:blood*; D012995:Solubility
chemical_list: D000596:Amino Acids; D015415:Biomarkers; D024042:Collagen Type I; D010281:Parathyroid Hormone; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; D019947:Receptors, Interleukin-6; C052929:collagen type I trimeric cross-linked peptide; C042813:procollagen type I carboxy terminal peptide; D015675:Osteocalcin; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; C036020:deoxypyridinoline; D003094:Collagen; D000469:Alkaline Phosphatase